泡沫温拌再生沥青高低温性能研究

为研究回收沥青掺量对泡沫温拌沥青高低温性能的影响,分别对掺加0%、20%、40%、60%、80%回收沥青的泡沫温拌沥青进行软化点、DSR和BBR试验。试验表明:随着回收沥青掺量的增加,泡沫温拌再生沥青的软化点、车辙因子和破坏温度值逐渐升高;当回收沥青的掺量达到60%及以上时,泡沫温拌再生沥青胶结料的高温性能明显改善;胶结料试样的低温抗裂性能随着回收沥青掺量比例的增加而逐渐降低,当回收沥青的掺量大于40%时,泡沫温拌再生沥青的蠕变劲度S和蠕变速率m值不能满足规范要求,低温抗裂性能较差;建议回收沥青的掺量小于60%。

Investigation on High and Low Temperature Properties of foamed warm-mix recycled asphalt

In order to investigate the influence of recycled asphalt content on high and low temperature properties of foamed warm-mix asphalt, the softening point test, dynamic shear rheological test and BBR test are conducted with 0%, 20%, 40%, 60%, 80% recycled asphalt. The results indicate that, with the increase of recycled asphalt content, the softening point, rutting factor and fail temperature of the foam warm-mix asphalt increase gradually, and the high temperature performance of the asphalt binder is obviously improved. The low temperature crack resistance of foamed asphalt decreases with the increase of the proportion of recycled asphalt content. When the recycled asphalt content is more than 40%, the creep stiffness and creep strain rate of the foamed asphalt cannot meet the requirements of the specification, and the low temperature cracking performance is poor. So the proper amount of recycled asphalt is less than 60%.